My vote goes to Black Hole spell, 3300-5500 Astral Damage 60 mana (38int). In the battle vs Uchkuk his army vs me lvl54 mage normal was "invincible", round 1 boom he had 1/5 of his army left with 1 spell i was like "OMG" Overpowered much.
Finished off the rest in the same round lol and done it couple more times for other late game battles like those damned Black dragons.. toast
